[pulseaudio-discuss] module-role-cork and mp3s

[Tanu Kaskinen]

On Thu, 2015-08-13 at 10:50 +0200, Mikhail Morfikov wrote:
> I have two streams one phone and one video/audio, and when I set the
> following:
> 
> load-module module-role-ducking trigger_roles=phone
> ducking_roles=music,video volume=60%
> 
> and I start playing an mp3, the volume is lowered to 60% and that's
> fine. Each time a new mp3 is being played the volume doesn't change,
> which is also a good thing.
> 
> There's another module module-role-cork and when it's enabled (also
> commenting out the line above), it acts a little bit strange. When I
> start the phone stream, the mp3 is muted, and that's expected, but 
> when
> another mp3 starts to play, the sound appears.
> 
> Should that happen?

Ideally that shouldn't happen, but currently we have a bit limited
support for managing corking. Currently applications are required to
cooperate when we want to cork them. module-role-cork sends a cork
request to an application, and the application will then obey that
request (or not, but in your case not obeying the request is not the
problem). To make this work on new streams too, module-role-cork should
send the cork request also when a new stream appears, which it
currently doesn't do. It could very well do that, so patches welcome!

Sending a cork request after a new stream has appeared isn't quite
optimal, since the beginning of the stream may already hit the speakers
before the corking happens, but that would still be better than the
current behaviour.

It would be good to have "server-side corking" that wouldn't require
cooperation from applications. That's a bit more complicated to
implement.

-- 
Tanu